This is not an atypical payment request from an enrichment class:
What could be better here?
- Due date could be better advertised
- No way to quickly pay the invoice via a link that includes a reference. 
- Total includes late fee. Am I already late? Huh?
- No way of me knowing if I have already paid this amount (assuming I forgot the next step)
- Expects a reply telling them the date of the transfer
 Paynow with a reference?!
Good for you and the vendor to have a hopefully unique way to identify what you paid for.
This in an ideal world would be part of the Paynow QR code. I enquired about getting a reference embedded in the payment and perhaps a Webhook (so the vendor knows the invoice was paid) and this is the reply from DBS:
For API solution, as this is a premium solutioning there will be an initial implementation setup fees starting at $25K payable to DBS. There will also be tech cost to be incurred for customer’s own system to be integrated with the API solution. Transaction cost via API will be advised further by the relevant team as it differs from product to product.